Means for controlling variable-speed gears.



J. D. DEAN. MEANS FOR CONTROLLING VARIABLE SPEED GEARS.

APPLICATION HLED MAR 30' 1918.

Patented Jan. 21, 1919.

LQ9L779.

UNITED STATES PATENT OFFICE.

JOHN DENMAN DEAN, OF JOHANNESBURG, TRANSVAAL, SOUTH AFRICA, ASSIGNOB- OF ONE-THIRD TO FREDERICK ARTHUR HOWORTH AND ONE-THIRD T HERBERT ANDERSON JARDINE, BOTH OF JOHANNESBURG, TRANSVAAL, SOUTH AFRICA.

Specification of Letters Patent.

Patented Jan. 21, 1919.

Application filed March 30, 1918. Serial No. 225,678.

To all whomit may concern:

Be it known that I, JOHN DENMAN DEAN, a British subject, and residing at 4 Sutherland avenue, Wanderers View, Johannesburg, Transvaal Province of the Union of South Africa, have invented certain new and useful Improvements in Means for Controlling Variable-Speed Gears, of which the following is a specification. 7

The present invention has reference to variable speed gears of the type commonly fitted to motor cars, in which the changes are effected by the engagement of different pairs of toothed wheels, a gear operating member being moved to successively difi'erent positions to bring thedifi'erent pairs into mesh.

The purpose of the invention is so to control the operation of the gear that the changing movements can be effected only when the wheels of the pair which is intended to be engaged are rotating approximately at their designed relative speeds or in other words when their tooth speeds are equal.

With this object the invention consists of a stop normally preventing movement of the operating member, means whereby the speeds of the gear elements are compared and means whereby the stop is removed when said speeds reach or approximate to the proper ratio.

In the accompanying drawings the invention is shown as embodied with a typical motor car change speed gear,

Figure I being a plan sectioned on M M Fig. III.

Fig. II an elevation of the gate and gear ope'rating'lever.

Fig. III an elevation of the gear box and its attached box 14, the cover of the latter being removed.

Fig. IV a detail view of the disks 29, 30 hereafter referred to viewed from the direction of the arrow E Fig. III, a portion of the disk 29 being broken away at F.

1 indicates a gear box, 2 a driving shaft and 3 a driven shaft. 4 is a gear control lever fast with a rocking and sliding shaft 5, and associated with a gate 6 of theusual motor car type. The lever is shown in the neutral position; by moving it into the different gate openings A, B, C, D, the shaft 5 is moved to efi'ect different arrangements of the gear wheels 7 whereby the shafts 2 and 3 are coupled with difl'erent velocity ratios which, will be indicated by 0,, b, c, d, respectively.

On the lever 4 is a stop 8 which projects at each side of the lever. Associatedv with each gate is a pawl '9 pivoted at 10. One end 11 is forked and tends to lie by gravity in such a position that upon the lever being moved to pass into its gate opening, said forked end engages the stop 8.

The other end 12 of the pawl armature associated with an electroma et 13. WVhen the electromagnet is energized it attracts the end 12 of the pawl, so lifting the forked end 11 suiliciently to clear the stop 8. The pawls and magnets proper to the different gate openings A, B, G, D, are distinguished when necessary by the addition of the indices (1, b, c, (1, respectively to the appertaining reference numerals. It will be seen that the lever 4 is unable to enter any of the gate'openings until the pawl 9 for that opening has been raised by the excitation of its electro magnet 13. The elec-. tro-magnets are energized at the proper moment to enable the gears to mesh quietly, by the mechanism described'hereunder.

On the r box 1 is a box 14 containin two devices, 15, 16 of the nature of centri ugal governors and designed to effect displacement of cooperating parts proportionately to the speed of the driving'and driven shafts 2, 3.

The devices shown each comprise a heavy rim 17 pivoted by an arbor 18 to the vertical spindle 19. A spring 20 tends to hold the rim angularly to the spindle, wh1le centr1 fugal force due to rotation of the sp ndle 19 tends to. move the rim toward a position at right angles to the spindle. The rim is connected by a rod 21 to a sleeve 22 capable of sliding u and down the spindle 19. Said sleeve is ormed with annular rack teeth 23 engaging a pinion 24; the arrangement being such that rotation of the sleeve does not affectthe pinion, while up or down movement of the sleeve rotates the P1111011. This type of centrifugal device is advantageous forms an' for car use since the point of support of the speed of rotation of the spindle 19, and with p this object it is arranged that the rim 17 does not vary greatly in position for the different speeds.

The spindle .19 of the device 15 is connected by gearing 25 to the shaft 2 and the spindle of the other device 16 is connected by gearing 26 to the shaft 3. The pinion of the device 15 is fast on a shaft 27 and the pinion of the device 16 is fast on a shaft 28. On said shafts are the insulating disks indicated by 29, 30 respectively. The disks 29, 30 are thus rotated by axial movement of their respective sleeves 22, and assume different positions relative to one another according to the relative speeds "of their respective centrifugal devices 15, 16.

Said disks are set facing one another and on the face of disk 30 is a spring contact pin 31. On the adjacent face of disk 29 are four contact plates 32 32", 32, 32, sunk flush with the surface. Said last named contacts are so disposed as to register respectively with the contact pin 31 when the shafts 2 and 3 are running at the several relative velocities proper to the several gear changes. For instance at the highest gear ratio a, contact 32 would touch the pin 31; at ratio 7) contact 32 would touch the pin 31; at ratio 0, the contact 32; and at ratio at the contact 32 The pin 31 is connected by a lead 33, ring 34, brush 35 and connection 36 to a circuit including a press button 37 on the lever 4, and a battery 38. The contacts 32*", 32, 32, 32 are severally connected by similar means, including the rings 39, 39, 39, 39? and brushes 40 40", 40, 40, to the electromagnets 13*, 13, 13, 13 respectively. The other ends of the magnet windings and the battery are eart-hed.

The device operates in the following manner. Assume the car to be running; when it is desired to change gear thelever 4 is moved toward the gate opening corresponding to the gear to be changed to e. 9. opening C. It is however prevented from passing into the opening by the pawl 9, and remains in neutral position, being held pressed lightly against said pawl ready to move when the awl lifts. At the same time the button 37 1s held depressed. When the engine speed has been brought to the'proper speed in relation to that of the car, the contact 32 touches the pin 31, the circuit is completed through the electromagnet 13, thus lifting the corresponding pawl 9 and allowing the lever 4 to enter the opening C, as indicated in dotted lines. thus changed at the moment when the velocity ratio of the shafts 2 and 3 is that atwhich the gears for velocity ratio a mesh clashing, For the same reason it is unnecessary to declutch when passing into the new gear. r

The. gear is Similar steps take place when changing into any oft-he other gears, the pawls 9, 9 9, being lifted when the contacts 32, 32", 32 respectively, touch the pin 31. It will be understood that the function of the press button 37 is simply to enable current to be used only when. required, the current being cut off automatically by the release of the button when the gear change has been completed.

In order that the gears may be changed in the ordinary way if so desired, the stop 8 is arranged to slide in a slot 41 in the lever 4. It is fitted with a rod 42 con nected to a lever 43, by lifting which the stop is raised clear of the pawls 9. The lever 43 can be retained in its lifted position by inserting a pin under it through a hole 44 in the lever. The sto 8 1s normally held down in its operative position by a spring 45. The stop 8 is raised when starting the car from rest since in this case the pawl 9 for the gate A cannot be raisedv owing to the shaft 3 being at rest.

I clanrn,

1. The combination of a drivingshaft, a driven shaft, variable speed gearing adapted toconnect said shafts with different velocity ratios, a gear operating member movable to different positions to change the gear, means preventing movement of the operating member to such positions and means actuated upon the driving and driven shafts assuming a predetermined velocity ratio to render said preventing means inoperative.

I 2. The combination of a driving shaft, a driven shaft, variable speed gearing adapted to connect said shafts with different velocity ratios, a gear operating mem er movable to different positions to change the gear, stop means limiting movement of said operating member, and mechanism for comparing the relative speeds of the shafts, said mechanism controlling the stop means to render .the latter inoperative when predetermined velocity ratios of the shafts are obtained. A

3. The combination of a driving shaft, a driven shaft, variable speed gearing adapted to connect said shafts with difi'erentvelocity ratios, a gear operating member movable to difi'erent positions to change the gear, locks controlling movement of the member to its several positions, and mechanism for comparing the relative speeds of the shafts, said mechanism controlling the locks to render them severally inoperative at different relative speeds.

4. The combination of a driving shaft, a

, driven shaft, variable speed gearing adapted properly, and the change is efiected without I to connect said shafts with different velocity ratios, a gear operating member movable mechanism responsive to the rotationof the shafts and" including difierent electrical circuits adapted to be energized severally according to the velocity ratio of the shafts, and locks for the gear operating member actuated by the energizing ot the electrical circuits.

5. The combination 01": a driving shaft, a driven. shalt, variable speed gearing adapted to connect said shafts with diti erent velocitv ratios. a gear operating member movable to different positions to change the gear, speed responsive mechanism actuated by the driving shaft, speed responsive mechanism actuated by the driven shalt, aicontact carrier for each such mechanism and adapted to be displaced according to the speed, contacts on said contact carriers brought into register according to the displacement of the contact carriers, and locks for the gear operating member severally in circuit with the different contacts.

(3. The combination ot a driving shaft, a driven shaft, variable speed gearing adapted to connect said shafts with different veloc- -it v ratios, gear operating means, locking devices therefor, speed responsive mechanism for each shaft consisting of a spindle driven by the shaft, a heavy rim pivoted for angular movement on the spindle a spring forcing said rim to an angular position with respect to the spindle. a sleeve slidable on the spindle, and connected to the rim, and members moving with each sleeve and cooperating to control the locking, devices.

7. The combination of a driving sha t, a driven shaft. variable speed gearing adapted to connect said shatt's with dill'erent velocity ratios. a gear operating lever for changing the gears, a gate having several gate openings into which the lever is moved for changing gear. a gravity pawl for each gate openinn' tending to hold the lever from entering said opening. and means responsive to given velocity ratios of the shafts for lifting the pawls singly.

In testimonv whereof I aliix my signature.

JOHN DENllL rN DEAN. 

